Rapid installation thermoplastic EME protection cap

Abstract

A cap assembly for enclosing an end portion of a bolt fastener includes a first cap member which includes a bore and a surface positioned within the bore which defines first threads and the first cap member also includes an external surface which defines second threads. A second cap member includes a sidewall which defines a receptacle with an opening which provides access to an interior of the receptacle and the sidewall includes an interior surface which defines third threads compatibly configured to engage the second threads. The third threads are positioned along the interior surface of the receptacle extending along a length of the receptacle a first distance and the second threads are positioned along the external surface of the first cap member extending along a length of the external surface a second distance wherein the first distance is greater than the second distance.

What is claimed: 
     
       1. A cap assembly for enclosing an end portion of a metallic bolt assembly, comprising:
 a first cap member includes:
 a bore which extends through at least a portion of the first cap member and a surface of the first cap member positioned within the bore defines first threads; and 
 an external surface defines second threads; and 
 
 a second cap member includes:
 a sidewall which defines a receptacle with an opening which provides access for the first cap member to be positioned within an interior of the receptacle; and 
 the sidewall of the receptacle includes an interior surface which defines third threads compatibly configured to engage the second threads of the external surface of the first cap member, wherein:
 the third threads are positioned along a length of the interior surface of the receptacle extending a first distance and the second threads are positioned along a length of the external surface of the first cap member extending a second distance; 
 the first distance is greater than the second distance; and 
 with the receptacle positioned on a surface, from which the end portion of the metallic bolt assembly extends, second cap assembly encloses and electrically isolates first cap assembly and the end portion of the metallic bolt assembly from an environment outside of the receptacle bounded by the surface and an external surface of the receptacle. 
 
 
 
     
     
       2. The cap assembly of  claim 1 , wherein the first cap member comprises one of a thermoplastic, thermoset or metallic material. 
     
     
       3. The cap assembly of  claim 1 , wherein the first cap member includes a pair of wrench flats positioned on the external surface of the first cap member. 
     
     
       4. The cap assembly of  claim 3 , wherein one of the pair of wrench flats is positioned spaced apart from another of the pair of wrench flats along the external surface of the first cap member with second threads extending between the pair of wrench flats. 
     
     
       5. The cap assembly of  claim 1 , with the first threads of the first cap member engaged to a threaded portion of threaded shaft of the metallic bolt assembly:
 the first threads engage in a range of one thread up to and including three threads of the threaded portion of threaded shaft of the metallic bolt assembly; and 
 the first cap member abuts a nut positioned on the threaded shaft of the metallic bolt assembly. 
 
     
     
       6. The cap assembly of  claim 1 , wherein the second cap member comprises one of a thermoplastic or, thermoset material. 
     
     
       7. The cap assembly of  claim 1 , wherein the second cap member includes a pair of wrench flats positioned spaced apart from one another along an external surface of the second cap member. 
     
     
       8. The cap assembly of  claim 1 , wherein a portion of the external surface of the receptacle comprises a cylindrical shape which includes an end surface. 
     
     
       9. The cap assembly of  claim 8 , wherein the end surface which extends in an angular direction with respect to the length of the interior surface of the receptacle. 
     
     
       10. The cap assembly of  claim 9 , wherein one of a sealant or an adhesive is positioned on the end surface. 
     
     
       11. A cap assembly for enclosing an end portion of a metallic bolt assembly, comprising:
 a first cap member includes:
 a bore which extends through at least a portion of the first cap member and a surface of the first cap member within the bore defines first threads; and 
 an external surface defines first teeth which extend in a direction away from the first cap member and which are positioned to extend along a length of the external surface; and 
 
 a second cap member includes:
 a sidewall which defines a receptacle with an opening which provides access for the first cap member to be positioned within an interior of the receptacle; and 
 the sidewall of the receptacle includes an interior surface which defines second teeth which extend in a direction away from the sidewall toward the interior of the receptacle and are positioned to extend along a length of the interior surface; wherein
 the second teeth extend along the length of the interior surface of the receptacle a first distance and the first teeth extend along the length of the external surface of the first cap member a second distance; 
 the first distance is greater than the second distance; and 
 with the receptacle positioned on a surface, from which the end portion of the metallic bolt assembly extends, second cap assembly encloses and electrically isolates first cap assembly and the end portion of the metallic bolt assembly from an environment outside of the receptacle bounded by the surface and by an external surface of the receptacle. 
 
 
 
     
     
       12. The cap assembly of  claim 11 , the first cap member comprises one of a thermoplastic, thermoset or metallic material. 
     
     
       13. The cap assembly of  claim 11 , wherein the first cap member includes a pair of wrench flats positioned on the external surface of the first cap member. 
     
     
       14. The cap assembly of  claim 13 , wherein the pair of wrench flats are positioned spaced apart from one another along the external surface of the first cap member. 
     
     
       15. The cap assembly of  claim 11 , with the first threads of the first cap member engaged to a threaded portion of a threaded shaft of the metallic bolt assembly:
 the first threads engage in a range of one thread up to and including three threads of the threaded portion of the threaded shaft of the metallic bolt assembly; and 
 the first cap member abuts a nut positioned on the threaded shaft of the metallic bolt assembly. 
 
     
     
       16. The cap assembly of  claim 11 , wherein the second cap member comprises one of a thermoplastic or thermoset material. 
     
     
       17. The cap assembly of  claim 11 , with the insertion of the first cap member into the interior of the receptacle an end portion of one tooth of the first teeth comes into contact with an end portion of one tooth of second teeth such that at least one end portion of the one tooth of the first teeth or the end portion of the one tooth of the second teeth flex permitting the one tooth of the first teeth to move past the one tooth of the second teeth. 
     
     
       18. The cap assembly of  claim 11 , wherein with the first cap member positioned within the interior of the receptacle at least one of:
 at least one tooth of the first teeth is positioned between two adjacent teeth of the second teeth, or 
 at least one tooth of the second teeth is positioned between two adjacent teeth of the first teeth. 
 
     
     
       19. The cap assembly of  claim 11 , wherein a portion of the external surface of the receptacle comprises a cylindrical shape which includes an end surface which extends in an angular direction relative to the length of the interior surface of the receptacle. 
     
     
       20. The cap assembly of  claim 11 , wherein one of a sealant or an adhesive is positioned on the end surface.